In recent years, an enormous amount of gene information is being revealed by genome analysis. In addition, the function of a gene and the relationship between gene information and a protein have also begun to be analyzed, and based on these findings, cell devices such as a sensor for trace amount analysis and a microreactor, which utilize the function of cells or microorganisms, have been actively studied.
Meanwhile, it has been known for a long time that a cell can construct a three-dimensional structure varying according to region, and studies on the ability of cells to form tissue of such high order have been progressing recently. If the mechanism of high order tissue formation of cells is elucidated and the reproduction or control thereof becomes possible, it will be possible to produce various kinds of replacement tissues with a higher biocompatibility than artificial tissues or artificial organs made from a conventional synthetic material, and therefore it also is drawing attention as a technique for organ transplantation.
In addition, recently hematopoietic stem cell transplantation method has attracted attention as a therapeutic method of cancers or leukemias; however, the available amount of hematopoietic stem cells is extremely small, therefore, techniques of large scale hematopoietic stem cell proliferation are being studied.
With regard to the above mentioned construction of cell devices, elucidation of the mechanism of the high order tissue formation of cells, and techniques of hematopoietic stem cell proliferation, etc., it is important to immobilize cells at a high density, and various methods for this have been proposed.
For example, a method which has been known for a long time involves immobilizing adherent cells on a support. Recently, a technique of limiting the adhesion region of cells with the use of a support to which adherent cells cannot adhere, or a support which has been treated so that adherent cells cannot adhere thereto and then making a microarray has been reported. For example, in Shuguang Zhang et al., Biomaterials 20, 1213-1220, 1999, it has been reported that by immobilizing a polyethylene glycol (PEG) and a PEG-cell adhesion peptide on the surface with gold foil intermediated by thiol, cells come to adhere to the region on which PEG-cell adhesion peptide has been immobilized without adhering to the region where PEG has been immobilized. In addition, in Junaid Ziauddin et al., Nature 411 (6833) 107-110, 2001, it has been reported that a mixed solution of DNA and gelatin is spotted in an array on a glass slide, and when adherent cells are added thereon and contact with it, cells incorporate genes present where the binding of cells to gelatin has taken place, and thereby an array of transient gene expressing cells can be formed.
However, the methods for immobilizing cells as above are all for adherent cells having the property that they adhere to a hydrophobic support or a collagen coated support, and the fact is that there are almost no known methods for immobilizing blood cells, hematopoietic stem cells, floating cells such as certain kinds of cancer cells, bacteria, phospholipid endoplasmic reticula, or the like.
If a highly versatile technique for immobilizing floating cells or bacteria in a living state is established, its usefulness in medical treatment and research would be high.
In addition, in regenerative medicine for skin or the like, to a scaffold or coating of collagen or the like, a method for immobilizing adherent cells has been applied. However adhesion and proliferation takes a long time, and furthermore, it is difficult to immobilize cells against gravitational force.
Accordingly, the invention of this application has taken the above situation into account and makes it an object to solve the problems of conventional techniques, providing an immobilization material in which, regardless of the type of cell, a floating cell, a bacterium, a phospholipid endoplasmic reticulum, or the like is immobilized on the surface of a solid phase, and to provide an inexpensive and convenient immobilization method for obtaining the same.